Liquid flow regulating means



Aug, 1, 1939. s. H. HALL LIQUID FLOW REGULATING MEANS Filed June '7, 195'? WIT/V555;

W w W Patented Aug. 1, 1939 2,187,837 LIQUID FLOW REGULATING MEANS Selden H. Hall, Poughkeepsie, .N.

Y., assignor to The De Laval Separator Company, New York, N. Y., a corporation of New Jersey Application June 7, 1937, Serial No. 146,825

Claims.

In liquid flow regulators, and particularly in flow regulators designed for use with centrifugal separators, it is known to maintain uniformity in the rate of flow of the liquid by positioning a throttling valve in the flow passage, creating, by suitable means, a diiference in pressure between two points in such passage, and providing means, responsive to that diflerene in pressure, to move the throttling valve toward the closed position on any increase of that difference and toward the open position on any decrease of that diflerence. Such flow regulators are disclosed in an application for patent filed by Hans 010i Lindgren and Nore Einar Bergner June 1, 1937, Serial No. 145,760.

The object of my invention is to provide a flow regulator, operating on the same generic principle and having certain advantages thereover in. smoothness of operation and in delicate responsiveness to differences of pressure.

A preferred embodiment of the invention is shown in the drawing, in which Fig. 1 is a longitudinal sectional view of a device, embodying my invention, positioned in the flow passage and Fig. 2 is a cross-section on the line 2-2 of Fig. 1.

Fitting closely in a cylindrical body a is a cylinder b. Nearly surrounding the cylinder are an inlet passage c and an outlet passage d. The wall of the cylinder has ports e communicating with the inlet passage and ports 1 communicating with the outlet passage. Fitting closely within the cylinder 1) and between the ports e and f is a ring g causing a restriction in the passage from one set of ports to the other. A set screw h entering a groove i in the ring holds it in place. A small hole 7 provides communication from the region of the minimum diameter portion of the ring to the groove 2 and another hole is, through the cylinder wall, provides communication from the groove ito anothergroove 1), in the wall of the body, leading to a counterbore 1n, iirthe upper end of the body, from which a notch n leads to the inside of the cylinder. A similar hole 0, groove p, counterbore q and notch 1' lead from the interior of the cylinder just below the ring g to the interior of the cylinder at its lower end. Freely movable within the cylinder is a piston having two heads .9 and t connected by a stem u.

When liquid flowing through the device passes from the space above the ring g to the restricted passage between the minimum diameter portion thereof and the stem u, a portion of its pressure energy is converted to velocity energy resulting in a substantially lower pressure at the center of length of the ring and in the hole 4. This difference in the pressure is proportional to the square of the velocity of flow and, being communicated to the, upper end of the piston head 8, is so much less than the pressure on the lower 5 end that the entire piston tends to move upward. Communication through the hole 0 groove p, counterbore q and notch r keeps the pressure the same at both ends of the lower piston head t, but as the passage is small exchange of liquid 10 will be slow and there will be a dash pot efiect to prevent sudden movements. The weight of the piston can be so selected that it will balance the upward tendency of the difierence in pressure due to any desired rate of flow. The cylinder and piston need not be positioned vertically and any other means, such, for example, as piston heads of different areas, tending to move the piston in one direction may be utilized. If the rate of flow increases he upward tendency will 2 overcome the weight oi' the piston and cause it to move upward, whereupon the lower piston head if will partially close the ports I and reduce the rate of flow until the upward tendency just balances the weight of the piston. If then there is a reduction in the rate of flow the difference in pressure and the upward tendency will be reduced and the piston will move downward, opening the ports I and allowing the flow to increase until balance is restored.

What I claim and desire to protect by Letters Patent is:

1. Means to maintain substantial uniformity in rate of flow of a liquid through a passage, which comprises a cylinder interposed in said 5 passage and provided with an inlet port communicating with an inflow section of the passage and an outflow port communicating with an outflow section of the passage, a piston reciprocable in the cylinder having two heads affording be- 40 tween them a passage between said ports and one of which heads is adapted in the movement of the cylinder in one direction to throttle said outlet port, said piston tending to move in a direction to open said outlet port, restriction means in the passage between said heads and ports adapted to convert pressure energy into velocity energy and expansion means therebeyond to reconvert velocity energy into pressure energy, means aifording fluid communication between the restricted portion of the passage and the end of the cylinder away from which the piston tends to move, means affording communication between said expanded part of the passage and the other-end of the cylinder, thereby creating differential pressures in opposite ends of the cylinder tending to move the piston in a direction opposite to that hereinbefore specified and throttle the outlet port, whereby variation in rate of flow in the inflow end of the passage will effect movement of the piston in one direction or the other until the forces tending move the piston in opposite directions are ced and the outlet port is held open to the 7 nt required to eflect a predetermined rate of liquid flow therethrough.

2. Means to maintain substantial uniformity in rate of flow of a liquid through a passage, which comprises a cylinder interposed in said passage and provided with an inlet port communicating with an inflow section of the passage and an outflow port communicating with an outfiow section of the passage,a piston reciprocable in the cylinder having two heads aflording between them a passage between said ports and one of which heads is adapted in the movement of the cylinder in one direction to throttle said outlet port, said piston tending to move in a direction to open said outlet port, a ring secured to and within the cylinder between said ports and contracted in internal diameter between its ends to thereby successively convert a part of the pressure energy into velocity energy and beyond said contraction reconvert velocity energy into pressure energy, said ring having a'groove adjacent the cylinder wall and an opening between the groove and its contracted part, the cylinder having openings communicating respectively with said groove and the part of the passage beyond the contracted part of the ring, channels one of which connects the first of said openings with the end of the cylinder away from which the piston tends to move and the other of which connects the other of said openings with the other end of the cylinder, thereby creating diflerential pressures in opposite ends of the cylinder tending to move the piston in a direction opposite to that specified and open the outlet port, whereby variation in rate of flow in the inflow end of the passage will effect movement of the piston in one direction or the other until the forces tending to move the piston in opposite directions are balanced and the outlet port is held open to the extent required to effect a predetermined rate of liquid flow therethrough.

' 3. In a flow regulating valve, the combination with a body having a bore therethrough with two enlargements thereof, one connected with an inlet passage and the other with an outlet passage and a hollow cylinderfltting closely within the bore and having through its wall two sets of ports one communicating with each of said enlargements, of a pressure energy to velocity energy and velocity energy to pressure energy converting ring within the cylinder between the two sets of ports and having at its small diameter and low pressure portion an orifice communicating with the inside of the cylinder at the end nearer to the inlet port, an orifice through the cylinder adjacent the side of the ring toward the outlet passage and communicating with the inside of the cylinder. at the end nearer to the outlet port and a piston reciprocable within the cylinder and having two heads and a stem holding them apart a distance equal to that of the outermost edges of the two sets of ports, means to cause the piston to normally move toward the end of the cylinder nearer to the outlet ports and means to stop said movement at a position which leaves both sets of ports wide open.

4. Means to maintain substantial uniformity in rate of flow of a liquid through a passage,-which comprises a cylinder interposed in said passage and provided with an inlet port communicating with an inflow section of the passage and an outlet port communicating with an outflow section of the passage, a piston in said cylinder operating as a valve to throttle said outlet port and having each of its faces under the influence of the pressure in the end of the cylinder adjacent to such face, means between said inlet port and said outlet port being first restricted to convert pressure'energy into velocity energy and thereby create a zone of relatively low pressure and beyond said restriction being enlarged to reconvert velocity energy to pressure energy and thereby create a zone of relatively high pressure, means providing forces adapted to hold the piston in position to maintain a uniform flow of liquid through the outlet port, said means including a pressure transmitting channel between said lower pressure zone and one end of the cylinder and a pressure transmitting channel between said higher pressure zone and the other end of the cylinder, any variation in the rate of liquid inflow thus changing said pressure differential and thereby moving the piston in one direction or the other to move said piston valve into position to effect an opening of the outlet port to the extent required to maintain the liquid outflow substantially constant.

5. Means to maintain substantial uniformity in rate of flow of a liquid through a e, which comprises a cylinder interposed in said passage and provided with an inlet port communicating with an inflow section of the passage and an outlet port communicating with an outflow section of the passage, a piston in said cylinder operating at a valve to throttle said outlet port and tending to move in a direction to hold said outlet port open, flow means between said inlet port and said outlet port, means successively restricting and enlarging said flow means to thereby convert pressure energy into velocity energy and create a relatively low pressure .zone and thereafter reconvert velocity energy to pressure energy and create a relatively high pressure zone, means aflording communication between the restricted low pressure zone and the end of the cylinder away from which the piston tends to move, and means aflording communication between the other end of the cylinder and said higher pressure zone between said restricted part of the passage and the outflow port, whereby the forces tending to move the piston in opposite directions may be balanced and whereby changes in pressure differential due to changes in rate of inflow will unbalance said forces until the piston valve effects an opening of the outlet port to the extent required to restore said balance.

BELDEN H. HALL. 

